WO1997001716A1

WO1997001716A1 - Hydraulic disengaging device for a friction clutch

Info

Publication number: WO1997001716A1
Application number: PCT/EP1996/002086
Authority: WO
Inventors: Ludwig Winkelmann; Jürgen OSTERLÄNGER; Christian Sperner
Original assignee: INA Wälzlager Schaeffler oHG
Priority date: 1995-06-24
Filing date: 1996-05-15
Publication date: 1997-01-16
Also published as: DE19680489D2; KR19990028286A; DE19680489B4; DE19523011A1; BR9609315A; KR100419704B1

Abstract

The invention concerns a hydraulic disengaging device (16) for a vehicle friction clutch. The proposed unit comprises a housing (2b) in whose central recess (4) a guide tube (6b) is inserted so as to leave a radial gap between it and an inner wall. A piston in the form of a telescopic piston (8b, 9b) is guided on the guide tube so as to be capable of sliding axially and bridge the radial gap between the guide tube (6b) and inner wall. In order to make the unit more compact, a disengaging device (1b) is provided and has a sleeve-shaped secondary piston (9b) which coaxially encloses a sliding primary piston (8b) guided on the guide tube (6b).

Description

description

Hydraulic release device for a friction clutch

The invention relates to a hydraulic release device for a friction clutch according to the features of the preambles of claims 1 and 29.

A release device of this type is known from JP 3-186 620-A. The structure of this disengaging device comprises a telescopic piston which is composed of two individual pistons which can be moved coaxially into one another in an end position. The respective hollow-cylindrical pistons have a relatively large wall thickness, which has a disadvantageous effect on the required radial installation space of the device. On the pressure chamber side, each piston is further provided with a radially outward extension in which an annular groove is made to accommodate a seal. The radially inner piston bears against the inner wall of the outer piston and the outer piston bears against the bore wall of the housing. A further seal is provided to seal an annular gap between a guide sleeve of the housing and the inner wall of the inner piston. Thus, the known disengaging device has, in addition to a space disadvantage, also a large range of parts with the consequence of a cost disadvantage.

It is therefore an object of the invention to provide a hydraulic disengaging device which is both space-saving and weight-optimized and which can be produced cost-effectively and has the advantages of assembly.

This object is achieved by the features mentioned in the characterizing part of claims 1 and 28. A hydraulic disengaging device constructed according to the invention is provided with a sleeve-like shaped secondary piston to form a telescopic piston, which coaxially encloses the primary piston in a touching manner. The primary piston is guided by its inner diameter on the guide sleeve and the secondary piston by its outer surface in the housing of the disengaging device. This piston arrangement advantageously enables a desired short, axial design. According to the innovation, the housing, which in previous designs with one-piece pistons, in addition to the guide sleeve, ensured guidance over almost the entire working stroke, has a reduced axial length, which results in a weight and cost advantage. The piston according to the invention further improves handling due to the reduced overall length, as a result of which the assembly can be simplified.

According to claims 2 and 3, a seal is provided for sealing the secondary piston in the housing, which is inserted in an annular groove which rests under prestress on the lateral surface of the secondary piston. To seal the primary piston, it is provided on the end face with a sealing ring, in particular with a groove sealing ring, the sealing lips of which, which are arranged in both edge zones of the sealing ring, lie on the outer surface of the guide sleeve on the one hand and on the other hand on the inner wall of the secondary piston.

It is expedient to use a groove sealing ring according to claim 4, which is non-detachably arranged on a reinforcement, which in turn is positively snapped onto the ring piston. Vulcanization, with which the two components are combined to form a unit, is advantageous for this purpose. Alternatively, the concept of the invention also provides a groove sealing ring in which the reinforcement is partially enclosed by the sealing material and a reinforcing section emerging from the groove sealing ring is fastened to the ring piston. The invention according to claim 5 ensures that the primary piston has a lower displacement resistance than the secondary piston. This mode of operation is achieved due to a smaller sealing diameter of the groove sealing ring which is provided for the primary piston in comparison to the seal which is used to seal the secondary piston in the housing. In addition, the relatively soft sealing lips of the groove sealing ring result in less friction than the sealing ring, which is guided in the housing under prestress and is guided in the housing, for sealing the secondary piston. Due to the different displacement resistance, when the release device according to the invention is actuated, which is triggered by actuation of the clutch pedal, the primary piston is initially displaced before the secondary piston is displaced.

According to claim 6, it is expedient to produce both the guide tube and the secondary piston without cutting by a deep-drawing process. The idea of the invention further provides for these inexpensive to produce drawn parts, for example. B. after gas nitriding and an intermediate treatment by honing brushes or polishing and a subsequent salt bath oxidation as corrosion protection in the disengaging device, so that previously customary, cost-intensive surface coatings in the guide bore of the housing can be dispensed with.

The configuration of the disengaging device according to the invention according to claims 7 and 8 provides that the secondary piston forms a stop on the housing via a collar pointing radially outwards (claim 7). To create a stroke limitation of the primary piston according to claim 8, the secondary piston is provided with a radially inward-pointing collar which engages over a shoulder on the primary piston and thus forms a stroke limitation for the primary piston.

Underlining the compact design, the housing is provided with an essentially rotationally symmetrical recess in which the Clutch release bearing can be added when the friction clutch is in an engaged position.

The embodiment of the invention according to claims 10 and 1 1 relates to the formation of the inner and outer ring of the clutch release bearing. According to claim 10, the disengaging device according to the invention is provided with a non-rotatably attached inner ring to the primary piston, and a rotatably arranged outer ring of the friction clutch. The embodiment according to claim 1 1, on the other hand, provides a non-rotatably indirectly connected outer ring to the primary piston and a circumferential inner ring.

To create a releasable fastening of the clutch release bearing, a positive, releasable bearing fixation is provided between the primary piston and a bearing ring of the clutch release bearing according to claim 12. If necessary, this arrangement enables the damaged part of the hydraulic release device to be replaced without the housing and the clutch release bearing having to be replaced together in the event of damage.

According to claim 13, a carrier disk is provided between the non-rotatably arranged outer ring of the clutch release bearing and the primary piston, the carrier disk being fastened to the primary piston by means of a positive snap fit in order to achieve simple, inexpensive assembly.

In order to create an effective seal between the inner ring and the outer ring of the clutch release bearing, a reinforced support disk is provided according to claim 14, which rests over a large area on a vertical section of the bearing inner ring, supported by the force of the plate spring. This support disk according to the invention effectively prevents disadvantageous lubricant leakage from the clutch release bearing and also enables both axial and radial adjustability of the outer ring. These measures favor the service life of the clutch release bearing. It is expedient, according to claim 15, to use a damping ring between the outer ring and the carrier disk, which prevents a damped, ie large radial deflection of the outer ring avoiding radial movement. According to the invention, a damping ring is provided on the inside of an outer ring collar of the outer ring, which rests on a concentric section of the guide sleeve by means of spring arms which are distributed over the circumference. The damping ring, which is preferably made of a plastic, has a plurality of elastic spring arms which span a radial distance and which allow a limited radial deflection of the outer ring from the clutch release bearing.

In an advantageous embodiment of the damping ring, claim 16 provides for this to be provided with an axial sealing lip on the end facing the side facing the clutch release bearing. For this purpose, the axial sealing lip is integrally formed as a radially inward-pointing shoulder on the damping ring and, at the radially inner end, bears against a vertical section of the carrier disk under prestressing. In accordance with the inner ring contour, an area is formed on this valve section that is complementary to the corresponding inner ring section; a labyrinth seal forms to avoid loss of lubricant.

In a further advantageous embodiment of the invention according to claim 1 7, both the inner ring and the outer ring have a section facing the housing, which are spaced radially from one another, the resulting space can be designed as a lubricant depot for lubricating the rolling elements of the Clutch release bearing. According to claim 18, a storage body filled with a lubricant can be inserted into the installation space, the storage body being able to be arranged both on the fixed or rotating inner ring or outer ring of the clutch release bearing for supplying lubricant to the rolling bodies. According to claim 19, conveying grooves are provided for the targeted supply of the lubricant, which are each arranged on the inner ring or outer ring opposite the lubricant depot or the storage body. The inventive idea according to claim 20 provides to arrange a molded ring which fills an annular gap which arises between the clutch release bearing and the housing when the friction clutch is engaged and, when the friction clutch is disengaged, protrudes into corresponding recesses in the housing. This advantageous embodiment effectively prevents dust from entering the rotationally symmetrical recess in the housing and the clutch release bearing as well as the guidance between the primary and secondary pistons.

According to claim 21, it may be advantageous that the secondary piston are assigned holding means which limit the actuating travel or fix the position of the secondary piston. This configuration enables multiple use of the secondary piston, for example, and thus helps to reduce costs and limit the number of parts. According to the invention, an adaptation of the maximum piston stroke by limiting or fixing the secondary piston is taken into account. The inventive idea according to claim 22 provides that a snap ring is inserted in the housing in an annular groove, which in the installed state engages in a circumferential groove of the secondary piston, the longitudinal extent of the circumferential groove exceeding the width of the snap ring and thus a stroke limitation of the secondary piston. Alternatively, it is provided according to claim 23 to insert a snap ring in a circumferential groove of the secondary piston, which in the installed position engages in the annular groove of the housing, the annular groove width exceeding the width of the snap ring.

In order to achieve a simple position fixing of the secondary piston, the invention provides for a snap ring positioned in the housing, which snap locks into a circumferential groove of the secondary piston which is adapted to the snap ring width.

An alternative position fixing of the secondary piston is provided according to claim 25, for this purpose the secondary piston is supported in the installed position with its one end on the ring flange of the guide sleeve and with its other End rests against a housing collar via a radially inwardly shaped collar. To create a sufficient passage cross-section in the area of the ring flange, this is provided in the contact area of the secondary piston with axially projecting projections on which the secondary piston is supported.

The claim 26 provides that in a die-casting process or Kunststoff¬ injection molding process for manufacturing the housing of the secondary piston is cast as an insert directly from the housing material, whereby a position fixing of the secondary piston is achieved at the same time. This manufacturing method advantageously eliminates the need to machine the bore for receiving the secondary piston. To optimize the position fixation it is provided according to claim 27 that the outer surface of the secondary piston is provided with at least one circumferential groove which is filled by the casting material in the manufacturing process of the housing.

The invention according to claim 28 provides for the arrangement of a compression spring to maintain a preload between the clutch release bearing and the clutch actuator spring. The construction according to the invention comprises a piston, consisting of a primary piston and a secondary piston, which are arranged coaxially longitudinally displaceable to one another and which form a telescopic piston. According to the design, the clutch release bearing is attached to the primary piston and a compression spring is inserted between the housing and a bearing ring of the clutch release bearing. This construction according to the invention does not require a pre-pressure valve and thus represents a cost reduction. In addition, there is a reduced component range, combined with a lower susceptibility to failure of the disengaging device.

An advantageous embodiment provides, according to claim 29, a carrier disk assigned to the primary piston, on which the clutch release bearing and the pressure spring are supported on one side. According to claim 30, the carrier disc is provided with an axially projecting shoulder on which a The spring end of the compression spring is under pre-tension. To this end, the idea of the invention provides that the attachment centers the spring end inside or outside.

In order to create an advantageous short overall length of the compression spring, a conical spring is provided according to claim 31, which also offers security against disadvantageous buckling and consequently does not require any guidance.

According to claim 32, it is expedient to provide a housing for a disengaging device which is provided in one piece with a connecting piece projecting radially from the clutch housing or in the direction of an outer wall of the clutch housing. This nozzle, which can also be referred to as a cast-on pipe, brings about a cost reduction since additional pipelines which are difficult to assemble can be dispensed with; it also reduces the number of joints to be sealed, i.e. H. the pipe screw connection directly on the housing is no longer necessary, as is the previously required alignment of the pipes during assembly.

In an advantageous embodiment of the invention according to claim 33, a separate flushing connection or ventilation connection is assigned to the line connection, via which the initial filling of the hydraulic system is simplified during the initial assembly of the hydraulic disengaging device and any subsequent ventilation of the system can also be carried out effectively. According to a preferred embodiment of the nozzle at the free end to be provided with a vent connection and a line connection, the connections being spaced parallel and arranged at right angles to the nozzle. In the installed state of the disengaging device according to the invention, these connections are led through an opening in the clutch housing, so that there is a simplified connection possibility.

According to claim 34, the connecting piece has two feed bores running parallel to one another, which correspond to tap holes made in the line connection and the vent connection. To achieve effective Sealing of the feed bores is provided according to claim 35 to seal these ends with a separate closure part, a ball.

To simplify the introduction of the ball into the longitudinal bores, the longitudinal bore is flared at the end. After reaching an end position, a positive caulking of a wall area of the longitudinal bore is also provided, which ensures a limited radial overlap of the ball, as a result of which the ball is held in a positive manner.

According to claim 37, as an alternative to a parallel arrangement, a staggered arrangement of the line connection and the ventilation connection is also provided depending on predetermined installation conditions, the flushing connection being arranged such that it assumes the statically highest installation position.

According to claim 38, the inventive concept comprises a one-piece design of the housing and the connecting piece. This unit can be produced inexpensively as a cast part, an aluminum die casting process is particularly suitable for this.

Further details of the invention can be found in the following description of four exemplary embodiments in a total of eighteen drawings. Show it:

Figure 1 in a half section a slave cylinder housing, in which a telescopic piston according to the invention in the pressurized

Condition is shown;

FIG. 2 shows a slave cylinder housing corresponding to FIG. 1 with a different primary piston seal;

FIG. 3 shows a release device in half section with the clutch release bearing arranged on the primary piston and having a circumferential outer ring in the engaged end position; Figure 4 shows the release device according to Figure 3 in the disengaged position (end position);

FIG. 5 shows a release device with a slave cylinder housing that is optimized in terms of installation space in the axial direction and in which the clutch release bearing is shown in the engaged end position;

Figure 6 shows the disengaging device shown in Figure 5 in the disengaged position (end position);

FIG. 7 shows a release device in half section, the clutch release bearing of which has a circumferential inner ring;

Figure 8 shows the release device according to Figure 7 in the disengaged position of the clutch release bearing (end position);

FIG. 9 shows a disengaging device which provides a groove sealing ring for sealing the pressure chamber, which has a reinforcement with which the groove sealing ring is snapped onto the primary piston in a form-fitting manner;

FIG. 10 shows the structure of a disengaging device according to the invention, in which a compression spring is used to dispense with a pre-pressure valve between the housing and a carrier disk assigned to the clutch release bearing;

Figure 1 1 a stroke limitation of the secondary piston of a release device according to the invention;

FIG. 12 shows a secondary piston inserted in a fixed position between the guide sleeve and the housing; FIG. 13 shows a snap ring inserted in the housing, which locks into a circumferential groove of the secondary piston in order to fix the position of the secondary piston;

FIG. 14 shows a secondary ring cast in a form-fitting manner;

FIG. 15 is a view of a disengaging device which is provided with a line and flushing connection which radially emerges from the housing;

FIG. 16 shows the release device according to FIG. 15 in a sectional view along line B-B;

FIG. 1 7 shows a release device in a longitudinal section, which represents a variant of the release device shown in FIG. 7;

Figure 18 is a sectional view of line A-A of Figure 1 7th

Figures 1 and 2 show the structure of a release device 1 a according to the invention, each in half section in the pressurized state. The disengaging device 1 a has a housing 2 a, which is attached via an end face 3 in the installed state to a gear housing not shown in FIGS. 1 and 2. A rotationally symmetrically designed, multiply stepped recess 4 is made centrally in the housing 2a. A guide sleeve 6a centered on the end face 3 via an annular flange 5 extends within the recess 4 while maintaining a radial distance from the recess 4 of the housing 2a. In Figures 1 and 2, the input shaft extending within the guide sleeve 6a is not shown, which connects a friction clutch to a manual transmission. A primary piston 8a is guided on a lateral surface 7 of the guide sleeve 6a, the primary piston 8a being in radial contact with the guide sleeve 6a via a narrow gap. In the primary piston 8a, grooves 24 are provided on a bore wall for lubricant would be ordered. The primary piston 8a, which has an annular cylindrical shape, is axially displaceable on the guide sleeve 6a. The secondary piston 9a coaxially surrounding the primary piston 8a is also inserted axially displaceably in the recess 4 of the housing 2a. A centering of the guide sleeve 6a is provided by a duplication 10 provided in the ring flange 5, which bears against a step 11 of the recess 4. The guide sleeve 6a also serves to receive a retaining ring 12 into which a shaft sealing ring (not shown) can be inserted. The retaining ring 12 has a stepped design and is centered in the guide sleeve 6a. The retaining ring 12 bears against the ring flange 5 over a vertical section. The primary piston 8a has on its outer surface at the end directed towards the friction clutch a driver 23 which interacts with the collar 16 of the secondary piston 9a.

A pressure chamber 13, which is enclosed by the housing 2a, the guide sleeve 6a, the primary piston 8a and the secondary piston 9a, is connected to a pressure medium source via a feed bore 14. Pressurizing the pressure chamber 13 causes an axial displacement of the primary piston 8a and the secondary piston 9a, whereby due to a different displacement resistance of the two pistons there is initially an axial displacement of the primary piston 8a until it reaches a stop 15 which is formed by a radially inward direction showing, circumferential collar 16 which engages over a shoulder 17 on the primary piston 8a. Then there is a synchronous axial displacement of the secondary piston 9a until its radially outwardly directed collar 18 bears against the housing 2, which together form a stop 19. When the piston movement is reversed, the primary piston 8a in turn initially shifts until a driver 20 inserted on the outside in the primary piston 8a comes into contact with the collar 16 of the secondary piston 9a, and then both pistons are displaced to an end position at which the collar engages 18 comes to the ring flange 5. The different displacement resistance between the primary piston 8a and the secondary piston 9a is determined by the sealing of both pistons trigger different frictional forces, especially due to the different sealing diameters.

The primary piston 8a is provided with a groove sealing ring 20a, the sealing lips of which bear on the guide sleeve 6a on the one hand and on the secondary piston 9a on the other hand. In the sealing gap between the secondary piston 9a and the housing 2a, starting from the pressure chamber 13, a sealing ring 21 is provided which is inserted in a circumferential groove of the housing 2a and bears against the secondary piston 9a under prestress. A wiper ring 22, likewise inserted in the housing 2a, is arranged axially offset from this. The smaller sealing diameter and the relatively soft sealing lips of the groove sealing ring 20a result in a lower displacement resistance than the seals connected to the secondary piston 9a. In contrast to Figure 1, Figure 2 shows an axially longer secondary piston 8a, which is flush with an end face of the housing 2a. In addition, the groove sealing ring 20 is snapped onto the primary piston 8a, in contrast to the form-fitting connection in FIG. 1.

In the further exemplary embodiments of disengaging devices according to the invention described below, the components which correspond to the first exemplary embodiment are provided with the same reference numbers but sometimes different indices, so that reference can be made to the description of the first exemplary embodiment with regard to their description.

Figures 3 and 4 show the release device 1 b, which is supplemented by a clutch release bearing 25b. In FIG. 3, the clutch release bearing 25b is completely laterally inserted into the housing 2b, for which purpose this has a recess 27b which corresponds to the contour of the clutch release bearing 25b and is introduced from an end face 26. The clutch release bearing 25b assumes this position when the friction clutch is engaged. The position of the clutch release bearing 25b shown in FIG. 4 corresponds to the released friction clutch (end position), in which the clutch release bearing 25b is axially displaced from the housing 2b. The structure of the clutch release bearing 25b provides an inner ring 28b, which is in an outwardly facing U-shaped Opening of a retaining plate 38 connected on one side to the primary piston 8b engages. To achieve a non-positive contact, a plate spring 30 is provided in the holding plate 38, which is inserted between a vertical section of the holding plate 38 and the inner ring 28b.

The clutch release bearing 25b is supported on the friction clutch via the circumferentially arranged outer ring 29b. Correspondingly, both the inner ring 28b and the outer ring 29b extend axially into the housing 2b, these sections 31, 32 radially spaced delimiting an installation space 33 into which lubricant for lubricating rolling elements 34 of the clutch release bearing 25b can be introduced . The lubricant supply can be arranged as a depot both on the inner ring 28b (see FIG. 3) and on the outer ring 29b (see FIG. 4). For the targeted supply of lubricant, conveying grooves 35 are provided on the inner ring 28b or outer ring 29b opposite the lubricant supply, via which grooves the lubricant can be supplied to the rolling elements 34. For the effective sealing of the installation space 33, a sheet metal sleeve 36 is attached to the outer ring 29b in a form-fitting manner, on the end of which a lip seal 37 abutting the inner ring 28b is vulcanized. In the area of the plate spring 30 there is further provided a seal 39 fastened to the holding plate 38, which rests with sealing lips on a vertical section of the outer ring 29b facing away from the contact side of the friction clutch.

The release device 1 c shown in FIGS. 5 and 6 is largely comparable to the release device 1 b (FIGS. 3 and 4). In contrast to the clutch release bearing 25b (FIGS. 3 and 4), an enlarged installation space is provided between the inner ring 28c and the outer ring 29c of the clutch release bearing 25c. A form ring 40 is fastened to the inner ring 28c, which prevents the inner ring 28c from rotating with one another due to the bearing friction torque by positive engagement of the guide cam 46c in a guide groove 47c. The shaped ring 40 C has a design that adapts to the contour of the recess 27c and when the rice is disengaged Exercise clutch (end position) partially engages in an opening 45 of the housing 2c.

The release device 1 d in FIGS. 7 and 8 is provided with a clutch release bearing 25d, the inner ring 28d of which rotates. The structure also shows an outer ring 29d, which is supported on a carrier disk 41d. The carrier disk 41d, which is provided with a double cross-section or in the region of the feed bore of the housing 2d with a double, is held in a rotationally fixed manner on the primary piston 8d by means of a snap 42. On the outside, the carrier disk 41d has a right-angled bend to form a guide cam 46d which engages in a guide groove 47d of the housing 2d and thus prevents the outer ring 29d from rotating. On the outer ring 29d, an angular plate 43 is attached in a rotationally fixed manner, which with its long radial leg, supported by the force of the plate spring 30, rests non-positively on the carrier disk 41d and which enables a radial and axial adjustment of the outer ring 29d. To seal an annular gap 44 between the inner ring 28d and the outer ring 29d, the lip seal 37 is used, which bears against the circumferential inner ring 28d and is held by means of the sheet metal sleeve 36, which is positively attached to the outer ring 29d.

The disengaging device 1 e according to FIG. 9 shows a groove sealing ring 20e for sealing the pressure chamber 13, which forms a unit with a reinforcement 20f. Vulcanization, which creates a permanent, non-detachable connection, is suitable for connecting the two components. The reinforcement 20f encloses the end area of the primary piston 8e facing the pressure chamber 13 and encloses an end area of the annular piston 8e with a cylindrical section. At the free end, the reinforcement 20f has a radially inwardly directed snap lug 20g, which latches into an annular groove 20h of the primary piston 8e in order to achieve a positive locking. The reinforcement 20f formed from sheet metal by a deep-drawing process is further provided with a shoulder 17, which forms a stop 15 with the collar 16 arranged radially inward at the end on the secondary piston 9e and thus a stroke limitation of the primary piston 8e. In contrast to the previously described disengagement Devices shows the disengaging device 1e a compression spring 48e, which is inserted between the housing 2e and the inner ring 28e, with which a preload can be maintained between the clutch release bearing 25e and the plate spring 30 and which makes it possible to dispense with a pre-pressure valve. The compression spring 48e is designed as a conical spring, which offers security against buckling and also ensures a short block length.

FIG. 10 shows a clutch release bearing 25f detachably arranged on the primary piston 8f. For this purpose, the primary piston 8f is provided on the end face with a bearing fixation 49f, on which a carrier disk 41f is detachably snapped. The compression spring 48f is supported on the carrier disk 41f on the housing side and the outer ring 29f of the clutch release bearing 25f on the opposite side. To show an axial and radial adjustability of the outer ring 29f, a support disk 50 is provided which, with a long leg, bears against a vertical section of the carrier disk 41f, supported by the force of the plate spring 30. A short leg arranged at right angles to the long leg of the support disk rests on the inside with a seal 50a on the outer ring 29f.

FIG. 11 shows the disengaging device 1g, which is provided with a stroke limitation of the secondary piston 9g. For this purpose, an annular groove 53g is made in the housing 2g for receiving a snap ring 52. In the installed position of the secondary piston 9g, the snap ring 52 engages in a circumferential groove 54g which is introduced into the lateral surface of the secondary piston 9g and whose longitudinal extension exceeds the width of the snap ring by a multiple. The difference between the snap ring width and the longitudinal extent of the circumferential groove 54g determines the stroke of the secondary piston 9g.

FIG. 12 shows a fixed-position secondary piston 9h, which is supported at one end on the ring flange 5 of the guide sleeve 6h and bears at its other end on a housing collar 51. To achieve a pressure medium transfer into the pressure chamber 13, the ring flange 5 is the Guide sleeve 6h provided with a plurality of circumferentially distributed projections 55 on which the secondary piston 9h is supported.

The disengaging device 1 i according to FIG. 13 shows a secondary piston 8i which is positioned by means of a snap ring 52 and which engages in an annular groove 53i, introduced in the housing 2i, in the installed position of the secondary piston 8i, in a circumferential groove 54i adapted to the width of the snap ring 52. The disengaging device 1 i is also provided with an anti-rotation device for the inner ring 28i, which is provided on the housing side with a molded ring 40i which is angled on the outside to form a guide cam 46i which engages in a guide groove 47i of the housing 2i.

A further alternative position fixing of a secondary piston can be found in the disengaging device 1 j according to FIG. 14. For this purpose, the secondary piston 9j is designed as an insert, i. H. in the production process of the housing 2j by means of a die-casting process or plastic injection molding process, the cylindrically shaped secondary piston 9j is directly surrounded by the material of the housing 2j. To improve a positive connection between the housing 2j and the secondary piston 9j, the lateral surface of the secondary piston 9j has two parallel grooves 54j which are spaced apart and which are filled by the material of the housing 2j during the manufacturing process. To create a releasable, form-fitting fixation of the clutch release bearing 25j, this is connected to the primary piston 8j via a bearing fixation 49j, for which purpose a locking ring inserted in the end of the primary piston 8j is used.

In Figures 1 5, 16, the disengaging device 1 k is shown, which has a nozzle 68 radially emerging from the housing 2 k. The end piece is provided at the end with two parallel spaced connections, a line connection 57 and a vent connection 58, which are arranged at right angles to the connection piece 68. In the installed state of the disengaging device 1 k, the line connection 57 and the ventilation connection 58 are guided through an opening 59 of the clutch housing 56 and thus allow access to the outside of the clutch housing 56. that the vent connection 58 or flushing connection is arranged so that it is in the installed state above the line connection 57, ie at the statically highest point of the hydraulic system, which ensures that the air trapped in the hydraulic system can be effectively vented if necessary.

The connecting piece 68 is further provided with two axially spaced feed bores 14a, 14b, which correspond to branch bores 69a, 69b, which are made in the line connection 57 and in the ventilation connection 58, respectively. To seal the feed bores 14a, 14b, these are at the end, d. H. effectively sealed with a ball 66 above an opening of the tap holes 69a, 69b. In an installed position of the ball 66, the ball 66 is held in a form-fitting manner by a caulking 67 provided radially in the direction of the center of the bore of the feed bore 14a, 14b. For simple insertion of the ball 66 into the socket 68, the feed bore 14a, 14b is flared at the end.

FIGS. 17 and 18 show the disengaging device 11, which is comparable in terms of the structure of the disengaging device 1 d according to FIGS. 7 and 8. An outer ring collar 63 of the outer ring 29I is supported on the carrier disk 41 1, which is positively connected to the primary piston 8 d by means of a snap 42, almost on the outer circumference on a vertical section. To achieve a radial adjustability of the outer ring 29I with respect to the carrier disk 41 1, a damping ring 61 is used, which is arranged between a section 64 arranged coaxially to the guide sleeve 6d, the carrier disk 41 1 and an inner wall of the outer ring collar 63. The damping ring 61 is centered on the inside on the section 64 via circumferentially distributed, elastically designed spring arms 62. This design of the damping ring 61 causes a damped radial deflection of the outer ring 29I toward the carrier disk 41 1. The damping ring 61, which is made in particular of a plastic material, is further provided on the end face facing the clutch release bearing 25l with an axial sealing lip 60 which has a radially inward, ie to the guide sleeve 6d forming shoulder that sealingly rests under prestress on a vertical section of the carrier disk 411. On the valve section an axially or radially the inner ring contour, in addition, is formed, which in cooperation with the described inner ring section forms a labyrinth seal. This effectively prevents contamination and lubricant from escaping with little friction. The structure of the damping ring 61 according to the invention, which has axial recesses 65 on the outside, is further illustrated in FIG. 18 in order to achieve improved elasticity, which simplifies the installation of the damping ring 61 on the outer ring collar 63. FIG. 18 also shows the inclined arrangement of the spring arms 62 in the installed state of the damping ring 61, which ensures that the spring arms 62 are biased against the carrier disk 411.

20th

Reference numerals

1 a release device 6f guide sleeve

1 b release device 6g guide sleeve

1 c release device 6h guide sleeve

1 d release device 6i guide sleeve

1 e release device 6j guide sleeve

1 f release device 6k guide sleeve

1 g release device 7 outer surface

1 h disengaging device 8a primary piston

1 i Release device 8b primary piston

1j disengaging device 8c primary piston

1 k disengaging device 8d primary piston

2a housing 8e primary piston

2b housing 8f primary piston

2c housing 8g primary piston

2d housing 8h primary piston

2e housing 8i primary piston

2f housing 8j primary piston

2g housing 8k primary piston

2h housing 9a secondary piston

2i housing 9b secondary piston

2j housing 9c secondary piston

2k housing 9d secondary piston

3 end face 9e secondary piston

4 recess 9f secondary piston

5 ring flange 9g secondary piston

6a guide sleeve 9h secondary piston

6b guide sleeve 9i secondary piston

6c guide sleeve 9j secondary piston

6d guide sleeve 9k secondary piston

6e guide sleeve 10 double 1 1 level 27e recess

12 retaining ring 27f recess

13 pressure chamber 27g recess 14a feed bore 27h recess 14b feed bore 27i recess

15 stop 27j recess

16 collar 28b inner ring

17 shoulder 28c inner ring

18 collar 28d inner ring 19 stop 28e inner ring

20 groove sealing ring 28f inner ring 20e groove sealing ring 28g inner ring 20f reinforcement 28h inner ring 20g snap nose 28i inner ring 20h ring groove 28j inner ring

21 sealing ring 29b outer ring

22 Wiper ring 29c outer ring

23 driver 29d outer ring

24 Groove 29e outer ring 25b clutch release bearing 29f outer ring 25c clutch release bearing 29g outer ring 25d clutch release bearing 29h outer ring 25e clutch release bearing 29i outer ring 25f clutch release bearing 29] outer ring 25g clutch release bearing 30 Belleville spring 25h clutch release bearing 31 section 25i clutch release bearing 32 section 25j clutch release bearing 33 mounting space 34k conveyor body 26z clutch release bearing

27b recess 36 sheet metal sleeve 27c recess 37 lip seal 27d recess 38 holding plate 39 Seal 54j circumferential groove 40c shaped ring 55 projection 40i shaped ring 56 clutch housing

41 d carrier plate 57 pipe connection 41 f carrier plate 58 vent connection

41 1 carrier plate 59 opening

42 Snap 60 Axial sealing lip

43 angle plate 61 damping ring

44 Annular gap 62 Spring arms 45 Opening 63 Outer ring collar

46c guide cams 64 section 46d guide cams 65 recess 46i guide cams 66 ball 47c guide groove 67 caulking 47d guide groove 68 socket 47i guide groove 69a spigot 48e pressure spring 69b spigot 48f pressure spring 48h pressure spring 48i pressure spring 48j pressure spring 48k pressure spring 49f bearing fixation 49h bearing fixation 49j bearing fixation

50 support disc 50a seal

51 housing tape

52 snap ring 53g ring groove

53i ring groove 54g circulation groove 54i circulation groove

Claims

Expectations

1. Hydraulic release device for a friction clutch of vehicles, with a housing (2a to 2d), in its central recess, radially spaced from an inner wall, a guide sleeve (6a to 6d) is inserted, on which a piston, designed as a Telescopic piston bridging a radial distance between the guide sleeve (6a to 6d) and the inner wall is axially displaceable, the piston with its one end sealed a circular pressure chamber (13) and with its other, facing away from the pressure chamber (13) Front side rests on a clutch release bearing (25b to 25d), the pressure chamber (13) being enclosed by the housing (2a to 2d) and the guide sleeve (6a to 6d) and can be acted upon by a pressure medium via a pressure medium source, characterized in that the Telescopic piston has a sleeve-like shaped secondary piston (9a to 9d), which is slidable g on the guide sleeve (6a to 6d) e coaxially surrounds the primary piston (8a to 8d).

2. Hydraulic release device according to claim 1, characterized in that the secondary piston (9a to 9d) is sealed via a sealing ring (21) inserted into an annular groove of the housing (2a to 2d).

3. Hydraulic disengaging device according to claim 1, characterized in that a the end face of the primary piston (8a to 8d) covering, on the primary piston (ben) (8a to 8d) arranged groove sealing ring (20) via sealing lips a seal between a sealing gap of the guide sleeve ( 6a to 6d) and the primary piston (8a to 8d) on the one hand and the secondary piston (9a to 9d) and the primary piston (8a to 8d) on the other. 4. Hydraulic disengaging device according to claim 3, characterized in that the groove sealing ring (20e) is non-detachably connected to a reinforcement (20f), the reinforcement (20f) being supported on the end face of the primary piston (8e) and positively snapped onto it (Figure 9) .

5. Hydraulic release device according to one of claims 2 or 4, da¬ characterized in that the primary piston (8a to 8d) has a lower displacement resistance than the secondary piston (9a to 9d).

6. Hydraulic release device according to claim 1, characterized in that a non-cutting by a deep-drawing guide sleeve (6a to 6d) and a secondary piston (9a to 9d) are used, on the uncoated outer surface (7) or inner wall, the sealing lips of Groove sealing rings (20) are guided.

7. Hydraulic disengaging device according to claim 1, characterized in that the secondary piston (9a to 9d) forms a stop (19) on the housing (2a to 2d) via a collar (18) pointing radially outward at the end.

8. Hydraulic release device according to claim 1, characterized in that at the end of the secondary piston (9a to 9d) facing the clutch release bearing (25b to 25d) a radially inwardly facing collar (16) is seen vor¬, an approach to the primary piston ( 8a to 8d) radially overlaps and ensures a stroke limitation for the primary piston (8a to 8d).

9. Hydraulic release device according to claim 1, characterized by a housing (2a to 2d), into which an essentially rotationally symmetrical recess (27b to 27d) is made, which corresponds to an outer contour of the clutch release bearing (25b to 25d).

10. Hydraulic release device according to claim 1, characterized by a primary piston (8b, 8c), on which an inner ring (28b, 28c) of the clutch release bearing (25b, 25c) is fixed in a manner fixed against relative rotation (FIGS. 3 to 6). 1 1. Hydraulic release device according to Claim 1, characterized by a clutch release bearing (25d, 250, which has an outer ring (29d, 29f) which is connected non-rotatably and indirectly to the primary piston (8d, 8f) and a circumferential inner ring (28d, 28f) (Figure 7, Figure 8, Figure 10).

12. Hydraulic release device according to claim 9, characterized by a clutch release bearing (25f, 25h, 25j) which is positively attached to the primary piston (8f) with a releasable position fixation (49f, 49h, 49j) (Figure 10, Figure

12, Figure 14).

13. Hydraulic release device according to one of the preceding claims, characterized by a guide cam (46d) which forms a bearing fixation for the clutch release bearing (25d), the guide cam (46d) being attached to the primary piston (8d) via a positive locking ( 42) held carrier disc (41 d), which is provided for supporting the outer ring (29d) and the radially outward-pointing guide cam (46d) for supporting the torque of the outer ring (29d) into the guide groove (47d) in the housing (2d) intervenes (Figure 8).

14. Hydraulic release device according to claim 13, characterized by a between the carrier disc (41 d, 41 f) and a plate spring (30) of the clutch release bearing (25d, 25f) arranged armored support plate (50) which, in addition to a seal, an axial and radial setting of the outer ring (29d, 29f) and supported by the force of the plate spring (30) over a large area against a vertical section of the carrier disc (41d, 41f) (Figure 8, Figure 10).

15. Hydraulic release device according to one of the preceding claims, characterized in that a damping ring (61) fastened on the inside to an outer ring collar (63) of the outer ring (29l) via spring arms (62) distributed elastically around the circumference on a concentrically Guide sleeve (6d) extending portion (64) of the carrier disc (41 1) abuts (Figure 17). 16. Hydraulic disengaging device according to claim 1 5, characterized gekenn¬ characterized in that the damping ring (61) on the face to the clutch release bearing (25I) facing side via a radially inwardly guided, on a vertical section of the carrier disc (41 1) adjacent axial sealing lip (60) and opposite it has an axially or radially complementary section to the adjacent contour of the inner ring (28d), which forms a labyrinth seal or a sliding seal with the inner ring section.

1 7. Hydraulic release device according to claim 1, characterized by axially extending in the direction of the housing (2 b), radially spaced

Sections of the inner ring (28b) and the outer ring (29b), which form an installation space (33), the installation space being provided as a lubricant depot (FIGS. 3 and 4).

18. Hydraulic release device according to claim 17, characterized gekenn¬ characterized in that on the fixed or rotating inner ring (28b) or outer ring (29b) a storage body is provided which ensures a lubricant supply of rolling elements (34) of the clutch release bearing (25b).

19. Hydraulic disengaging device according to claim 1 7 or 18, gekennzeich¬ net by conveying grooves (35), via the lubricant to the rolling elements (34) are feedable, the conveying grooves (35) respectively the inner ring opposite the lubricant depot or the storage body ( 28b) or outer ring (29b) are assigned.

20. Hydraulic release device according to claim 1, characterized by a shaped ring (40) which largely fills an annular gap that results between the clutch release bearing (25c) and the housing (2c) and, when the friction clutch is disengaged, partially through an axial section in recesses in the housing (2c ) engages and supports a frictional torque of the inner ring (28c) in the housing (2c) by the positive connection. 21. Hydraulic release device according to claim 1, characterized gekennzeich¬ net that the secondary piston (9g to 9j) are assigned holding means which trigger a travel limit or position fixation of the secondary piston (9g to 9j).

22. Hydraulic release device according to claim 21, characterized gekenn¬ characterized in that a snap ring (52) is inserted in the housing (2g) in an annular groove (53g), which engages in a circumferential groove (54g) of the secondary piston (9g), the longitudinal extent the circumferential groove (54g) exceeds the width of the snap ring (52) (Figure 1 1).

23. Hydraulic Ausrückvorrichung according to claim 21, characterized by a secondary piston, in the circumferential groove of which the snap ring is inserted, which engages in the installed position in the annular groove of the housing, the longitudinal extension of which exceeds the width of the snap ring.

24. Hydraulic release device according to claim 21, characterized in that a snap ring (52) positioned in the housing (2i) is locked in a circumferential groove (54i) of the secondary piston (9i) adapted to the snap ring width in order to fix the position of the secondary piston (9i). Figure 13).

25. Hydraulic release device according to claim 21, characterized gekennzeich¬ net that the secondary piston (9h) is supported in the installed position with its one end at the annular flange (5) of the guide sleeve (6h), axially projecting projections (55) and with its further end rests against a housing collar (51) via a collar (16) molded radially inwards (FIG. 12).

26. Hydraulic release device according to claim 21, characterized in that in a die-casting process or plastic injection molding process for producing the housing (2j) the secondary piston (9j) is directly overmolded as an insert (FIG. 14). 27. Hydraulic release device according to claim 26, characterized gekenn¬ characterized in that for the axial fixation of the secondary piston (9j) this is provided with at least one circumferential groove (54j) which is filled by the casting material during the manufacturing process of the housing (2j).

28. Hydraulic release device for a friction clutch of vehicles, with a housing (2e to 2k), in its central recess, radially spaced from an inner wall, a guide sleeve (6e to 6k) is inserted, on which a piston, a radial distance is axially displaceably guided between the guide sleeve and the inner wall, the piston sealing with its one end side delimiting an annular pressure chamber (13) and with its other end side facing away from the pressure chamber (13) on a clutch release bearing (25e to 25k) The pressure chamber (13) is enclosed by the housing (2e to 2k) and the guide sleeve (6e to 6k) and can be acted upon by a pressure medium via a pressure medium source, characterized in that the piston has a primary piston (8e to 8k ) and a secondary piston (9e to 9k), which form a telescopic piston longitudinally displaceable coaxially with each other, with between the A compression spring (48e to 48k) is inserted in the housing (2e to 2k) and the clutch release bearing (25i to 25k) attached to the primary piston (8e to 8k).

29. Hydraulic release device according to claim 28, characterized gekenn¬ characterized in that the primary piston (8f) is assigned a carrier disc (41 f) on which on one side of the outer ring (29f) of the clutch release bearing (25f) abuts and the compression spring ( 48f) is supported (Figure 10).

30. Hydraulic release device according to claim 29, characterized gekenn¬ characterized in that the carrier disc (41 f) is provided with an axially projecting extension on which a spring end of the compression spring (48f) is centered.

31 Hydraulic release device according to claim 28, characterized gekenn¬ characterized in that the compression spring (48e to 48k) is designed as a conical spring and their Spring ends are frictionally and / or positively supported in the housing (2e to 2k) and on the clutch release bearing (25e to 25k) or on the carrier disk (41 f).

32. Hydraulic release device according to claim 28, characterized by a housing (2k) which is provided in one piece with a nozzle (68) projecting radially in the direction of an outer wall of a clutch housing (56), via which pressure medium can be fed to the release device (Figure 16 ).

33. Hydraulic release device according to claim 32, characterized in that the connecting piece (68) at the free end with a vent connection

(58) and a line connection (57) which are spaced parallel and at right angles to the nozzle (68).

34. Hydraulic release device according to claim 33, characterized in that the nozzle (68) over two parallel to each other

Feed bores (14a, 14b) which correspond to tap holes (69a, 69b) made in the line connection (57) and the vent connection (58).

35. Hydraulic release device according to claim 34, characterized gekenn¬ characterized in that the feed bores (14a, 14b) are each sealed by means of a closure part designed as a ball (66).

36. Hydraulic release device according to claim 34, characterized in that the feed bores (14a, 14b) are flared at the ends and the ball (66) is held in a form-fitting manner in each case by an interlocking caulking (67).

37. Hydraulic release device according to claim 32, characterized by an offset arrangement of the line connection (57) to the flushing connection

(58). 38. Hydraulic release device according to claim 32, characterized by a one-piece design of the housing (2k) and the connecting piece (68), this unit being made of aluminum.